The Border Gateway Protocol (BGP) is a protocol that is used to make core routing decisions on large networks such as the Internet. BGP maintains tables identifying Internet Protocol (IP) networks or autonomous system (AS) prefixes that indicate network reachability among the autonomous systems. Autonomous system prefixes are numbers assigned in blocks by the Internet Assigned Numbers Authority (IANA) to Regional Internet Registries. The autonomous system prefix blocks are, in turn, assigned to various Internet Service Providers (ISPs) by the Regional Internet Registries. BGP is a path vector protocol by which routing decisions are made based on path, network policies and/or rule-sets. In this regard, it is more appropriately termed a reachability protocol rather than a routing protocol. Most Internet service providers use BGP to establish routing between one another. Therefore, even though most Internet users do not use BGP directly, BGP is one of the more important protocols of the Internet.